We used a data size of in our simulations.
The MFCC spectral model we used is specified by
(10.5), where is given in table
10.1 and the columns of
are the MEL band functions (Hanning-shaped MEL band functions
calculated for a sample rate of 16000 Hz).
Table 10.1:
Coefficients that define the MFCC-like model
used in the simulations.
Coef
Value
Coef
Value
6.940937
21.734748
7.371341
140.720039
7.981074
47.916180
10.167393
8.350037
To make the simulations more ``interesting",
we made the AR and MFCC model spectra as
similar as possible by approximating the MFCC
power spectrum with an AR model. Thus, we created the AR
model by inverting the MEL cepstrum to obtain
the ACF, then used the Levinson
algorithm to obtain the following AR(2) model
.
These coefficients were used to create the
circular AR models (10.4).
The AR and MFCC-like spectra are plotted in Figure
10.1, which also shows the
sample mean power spectra from 1000 samples of each model.
Figure 10.1:
Power spectra, theoretical (smooth curves)
and estimated (symbols). Circles: AR, Triangles: MFCC.
Both spectra produce the same AR features.